1. Field of the Invention
The present invention relates generally to the separation of electrical transmission conductors or the like and, more specifically, is directed toward a device for maintaining a predetermined minimum spacing between individual conductors in a bundled conductor transmission line, while at the same time suppressing and damping undesired vibrations and oscillations of the conductors.
2. Description of the Prior Art
Damage to individual conductors in bundled electrical transmission conductors may be caused by the vibration and oscillation of the conductors. Such undesired motions may be induced by the wind, and may have longitudinal, transverse and vertical components. The longitudinal components are movement parallel to the ground longitudinally along the axis of the conductor. The transverse components are parallel to the ground, but perpendicularly of the conductor. The vertical components are movements of the conductor perpendicular to the ground. Suppression of these vibrations and oscillations requires a resilient connection between the means by which all the conductors in a bundle are spaced from one another, the spacer, and the means by which each conductor is clamped to the spacer, the clamps, allowing a limited amount of flexing to occur. Since both longitudinal and transverse oscillations may occur simultaneously, the spacer and clamps must permit limited movement of the individual conductors longitudinally and transversely relative to each other in order that such oscillations may be suppressed.
The motion of the conductors in a bundle may also be caused by electrical power surges, which cause the conductors in a bundle to be attracted toward the center thereof. For example, in a bundle of three conductors defining, in cross section, a triangle, a surge causes the conductors to be attracted to a point at the center of the triangle. Similarly, in a bundle of four conductors defining, in cross section, a quadrilateral, a surge causes the conductors to be attracted to a point at the center of the quadrilateral.
Prior-art devices have not provided wholly satisfactory results. For example, U.S. Pat. No. 3,978,276 to Poffenberger et al. shows a rigid spacer composed of mating half-sections having hollow spherical sockets for receiving the spherical end portions of individual conductor connector structures. The opposite ends of the connectors are fashioned for effecting a gripping connection with a conductor. A resilient damping material is interposed between the spherical connector end portions and their associated receiving sockets, and is secured to both the ball and the socket so that, on pivoting of the connector arm attendant conductor vibration or oscillation, the damping material is placed in shear to effect a damping action. However, the amount of flexing movement permitted by this device has not proven to be sufficient to bring about a satisfactory damping of the oscillatory motions of the individual conductors in a bundle.
The object of the present invention is to provide an improved spacer-damper superior to those of the prior art, such as that shown in U.S. Pat. No. 3,978,276.